<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <!-- 外部引入 -->
    <script src="./js/javascript.js"></script>
    <!-- <script>
        alert("aaa");
    </script> -->
</head>
<body>
     <!-- <script>
        alert("bbb");
    </script> -->
    <a href="javascript:alert('超链接')">链接</a>
    <button onclick="alert('按钮')">点一下</button>
</body>
</html>